A switch array can be used as a sensor to measure a parameter. In implementing the switch array as a measuring device, the array is designed so that the electrical state of the switches are altered in relation to the measurement of the parameter. To limit the number of connection terminals to the array, resistors may be connected between the switches so that, with the individual closing of each switch, the array circuit has a different impedance. With this arrangement, the array can be used with just two connecting terminals. One problem with this arrangement, however, is that the resolution of the sensor is limited by the number of switches in the array.
One known way to increase sensor resolution is to allow more than one switch to be closed at certain times, and take the impedance measurements of two circuits created by the state of the switches. This approach, however, requires three or more connections to the sensor.
Another method of increasing the resolution of the sensor is increasing the number of switches and resistors in the array. This, however, increases the cost of the sensor. Because of the above limitations, switch array sensors are often discarded in favor of other types of sensors.